US6268985B1ExpiredUtility
Read head having spin valve sensor with improved capping layer
Est. expiryMar 30, 2019(expired)· nominal 20-yr term from priority
Inventors:Mustafa Pinarbasi
H01F 10/3272B82Y 25/00G01R 33/093G11B 5/3932G11B 5/398G11B 2005/3996B82Y 10/00G11B 5/3903G11B 5/40G11B 5/3163
88
PatentIndex Score
49
Cited by
4
References
61
Claims
Abstract
A capping layer including thin films of ruthenium (Ru) and a metallic oxide are employed with a spin valve sensor for maintaining the MR coefficient (dr/R) of the spin valve sensor after being subjected to annealing steps which simulate hard balance of the photoresist layers in the insulation stack of a write head.
Claims
exact text as granted — not AI-modifiedI claim:
1. A magnetic read head comprising:
a spin valve sensor, the spin valve sensor including:
a ferromagnetic free layer structure;
a ferromagnetic pinned layer structure;
a nonmagnetic electrically conductive spacer layer located between the free layer structure and the pinned layer structure;
an antiferromagnetic pinning layer exchange coupled to the pinned layer structure for pinning a magnetic moment of the pinned layer structure;
the pinned layer structure being located between the pinning layer and the spacer layer;
a cap layer structure including a ruthenium (Ru) layer and a metal oxide layer; and
the ruthenium (Ru) layer interfacing the free layer structure and being located between the metal oxide layer and the free layer structure.
2. A magnetic read head as claimed in claim 1 wherein the pinned layer structure is an antiparallel (AP) pinned layer structure that comprises:
first and second ferromagnetic pinned layers with the first pinned layer being pinned by the pinning layer in a first direction; and
an antiparallel coupling layer located between the first and second pinned layers so that the second pinned layer is pinned antiparallel to said first direction in a second direction.
3. A magnetic read head as claimed in claim 1 wherein the pinned layer structure consists of a single ferromagnetic pinned layer.
4. A magnetic read head as claimed in claim 1 wherein the read head further includes:
electrically conductive first and second lead layers connected to first and side edges of the spin valve sensor;
nonmagnetic electrically insulative first and second read gap layers;
the spin valve sensor and the first and second lead layers being located between the first and second read gap layers;
ferromagnetic first and second shield layers; and
the first and second gap layers being located between the first and second shield layers.
5. A magnetic read head as claimed in claim 4 wherein the metal oxide layer is nickel oxide (NiO).
6. A magnetic read head as claimed in claim 5 including:
the free layer structure having a nickel iron (NiFe) layer and a cobalt iron (CoFe) layer; and
the cobalt iron (CoFe) layer being located between the nickel iron (NiFe) layer and the ruthenium (Ru) layer.
7. A magnetic read head as claimed in claim 6 further comprising:
the cap layer structure also including a tantalum (Ta) layer; and
the tantalum (Ta) layer having a thickness in a range of 20-100 Å.
8. A magnetic read head as claimed in claim 7 wherein the ruthenium (Ru) layer has a thickness of 10 Å.
9. A magnetic read head as claimed in claim 4 wherein the ruthenium (Ru) layer has a thickness in a range of 3-30 Å.
10. A magnetic read head as claimed in claim 9 wherein the metal oxide layer is selected from a group comprising nickel oxide (NiO), tantalum oxide (Ta 2 O 3 ) and aluminum oxide (Al 2 O 5 ).
11. A magnetic read head comprising:
a spin valve sensor, the spin valve sensor including:
a ferromagnetic free layer structure;
a ferromagnetic pinned layer structure;
a nonmagnetic electrically conductive spacer layer located between the free layer structure and the pinned layer structure;
an antiferromagnetic pinning layer exchange coupled to the pinned layer structure for pinning a magnetic moment of the pinned layer structure;
the pinned layer structure being located between the pinning layer and the spacer layer;
a cap layer structure including a ruthenium (Ru) layer and a metal oxide layer;
the ruthenium (Ru) layer being located between the metal oxide layer and the free layer structure;
the ruthenium (Ru) layer having a thickness in a range of 3-30 Å; and
the metal oxide layer being selected from a group comprising nickel oxide (NiO), tantalum oxide (Ta 2 O 3 ) and aluminum oxide (Al 2 O 5 ); and
the metal oxide layer having a thickness in a range of 5-50 Å;
electrically conductive first and second lead layers connected to first and side edges of the spin valve sensor;
nonmagnetic electrically insulative first and second read gap layers;
the spin valve sensor and the first and second lead layers being located between the first and second read gap layers;
ferromagnetic first and second shield layers; and
the first and second gap layers being located between the first and second shield layers.
12. A magnetic read head as claimed in claim 11 wherein the cap layer structure further includes a tantalum (Ta) layer with the metal oxide layer being located between the ruthenium (Ru) layer and the tantalum (Ta) layer.
13. A magnetic read head as claimed in claim 12 wherein the tantalum layer has a thickness in a range of 20-100 Å.
14. A magnetic read head as claimed in claim 13 including:
the free layer structure having a nickel iron (NiFe) layer and a cobalt iron (CoFe) layer; and
the cobalt iron (CoFe) layer being located between the nickel iron (NiFe) layer and the ruthenium (Ru) layer.
15. A magnetic read head as claimed in claim 14 wherein the cobalt iron (CoFe) layer has a thickness in a range of 3-20 Å.
16. A magnetic read head as claimed in claim 15 wherein the pinned layer structure is an antiparallel (AP) pinned layer structure that comprises:
first and second ferromagnetic pinned layers with the first pinned layer being pinned by the pinning layer in a first direction; and
an antiparallel coupling layer located between the first and second pinned layers so that the second pinned layer is pinned antiparallel to said first direction in a second direction.
17. A magnetic read head as claimed in claim 15 wherein the pinned layer structure consists of a single ferromagnetic pinned layer.
18. A magnetic read head comprising:
a spin valve sensor, the spin valve sensor including:
a ferromagnetic free layer structure;
a ferromagnetic pinned layer structure;
a nonmagnetic electrically conductive spacer layer located between the free layer structure and the pinned layer structure;
an antiferromagnetic pinning layer exchange coupled to the pinned layer structure for pinning a magnetic moment of the pinned layer structure;
the pinned layer structure being located between the pinning layer and the spacer layer;
a cap layer structure including a ruthenium (Ru) layer and a metal oxide layer;
the ruthenium (Ru) layer being located between the metal oxide layer and the free layer structure;
the ruthenium (Ru) layer having a thickness of 10 Å;
the metal oxide layer being nickel oxide (NiO);
the metal oxide layer having a thickness of 25 Å;
the free layer structure having a nickel iron (NiFe) layer and a cobalt iron (CoFe) layer;
the cobalt iron (CoFe) layer being located between the nickel iron (NiFe) layer and the ruthenium (Ru) layer;
the cap layer structure also including a tantalum (Ta) layer; and
the tantalum (Ta) layer having a thickness in a range of 20-100 Å;
electrically conductive first and second lead layers connected to first and side edges of the spin valve sensor;
nonmagnetic electrically insulative first and second read gap layers;
the spin valve sensor and the first and second lead layers being located between the first and second read gap layers;
ferromagnetic first and second shield layers; and
the first and second gap layers being located between the first and second shield layers.
19. A magnetic read head as claimed in claim 18 wherein the tantalum layer has a thickness of 35 Å.
20. A magnetic read head as claimed in claim 19 wherein the cobalt iron (CoFe) iron layer has a thickness of 5 Å.
21. A magnetic head assembly comprising:
a write head including:
first and second pole piece layers;
each of the first and second pole piece layers having a yoke portion located between a pole tip portion and a back gap portion;
a nonmagnetic electrically insulative write gap layer located between the pole tip portions of the first and second pole piece layers;
an insulation stack with at least one coil layer embedded therein located between the yoke portions of the first and second pole piece layers; and
the first and second pole piece layers being connected at their back gaps portions; and
a read head including:
a spin valve sensor that has first and second side edges;
first and second lead layers connected to the first and second side edges of the spin valve sensor;
nonmagnetic electrically insulative first and second read gap layers;
the spin valve sensor and the first and second lead layers being located between the first and second read gap layers;
a ferromagnetic first shield layer; and
the first and second read gap layers being located between the first shield layer and the first pole piece layer; and
the spin valve sensor including:
a ferromagnetic free layer structure;
a ferromagnetic pinned layer structure;
a nonmagnetic electrically conductive spacer layer located between the free layer structure and the pinned layer structure;
an antiferromagnetic pinning layer exchange coupled to the pinned layer structure for pinning a magnetic moment of the pinned layer structure;
the pinned layer structure being located between the pinning layer and the spacer layer;
a cap layer structure having a ruthenium (Ru) layer and a metal oxide layer; and
the ruthenium (Ru) layer interfacing the free layer structure and being located between the metal oxide layer and the free layer structure.
22. A magnetic head assembly as claimed in claim 21 including:
a ferromagnetic second shield layer;
a nonmagnetic isolation layer; and
the isolation layer being located between the second shield layer and the first pole piece layer.
23. A magnetic head assembly as claimed in claim 21 wherein the pinned layer structure is an antiparallel (AP) pinned layer structure that comprises:
first and second ferromagnetic pinned layers with the first pinned layer being pinned by the pinning layer in a first direction; and
an antiparallel coupling layer located between the first and second pinned layers so that the second pinned layer is pinned antiparallel to said first direction in a second direction.
24. A magnetic head assembly as claimed in claim 21 wherein the pinned layer structure consists of a single ferromagnetic pinned layer.
25. A magnetic head assembly as claimed in claim 21 wherein the ruthenium (Ru)layer has a thickness in a range of 3-30 Å.
26. A magnetic head assembly as claimed in claim 25 wherein the metal oxide layer is selected from a group comprising nickel oxide (NiO), tantalum oxide (Ta 2 O 3 ) and aluminum oxide (Al 2 O 5 ).
27. A magnetic head assembly comprising:
a write head including:
first and second pole piece layers;
each of the first and second pole piece layers having a yoke portion located between a pole tip portion and a back gap portion;
a nonmagnetic electrically insulative write gap layer located between the pole tip portions of the first and second pole piece layers;
an insulation stack with at least one coil layer embedded therein located between the yoke portions of the first and second pole piece layers; and
the first and second pole piece layers being connected at their back gaps portions; and
a read head including:
a spin valve sensor that has first and second side edges;
first and second lead layers connected to the first and second side edges of the spin valve sensor;
nonmagnetic electrically insulative first and second read gap layers;
the spin valve sensor and the first and second lead layers being located between the first and second read gap layers;
a ferromagnetic first shield layer; and
the first and second read gap layers being located between the first shield layer and the first pole piece layer; and
the spin valve sensor including:
a ferromagnetic free layer structure;
a ferromagnetic pinned layer structure;
a nonmagnetic electrically conductive spacer layer located between the free layer structure and the pinned layer structure;
an antiferromagnetic pinning layer exchange coupled to the pinned layer structure for pinning a magnetic moment of the pinned layer structure;
the pinned layer structure being located between the pinning layer and the spacer layer;
a cap layer structure having a ruthenium (Ru) layer and a metal oxide layer;
the ruthenium (Ru) layer being located between the metal oxide layer and the free layer structure;
the ruthenium (Ru)layer having a thickness in a range of 3-30 Å;
the metal oxide layer being selected from a group comprising nickel oxide (NiO), tantalum oxide (Ta 2 O 3 ) and aluminum oxide (Al 2 O 5 ; and
the metal oxide layer having a thickness in a range of 5-50 Å.
28. A magnetic head assembly as claimed in claim 27 wherein the cap layer structure further includes a tantalum (Ta) layer with the metal oxide layer being located between the ruthenium (Ru) layer and the tantalum (Ta) layer.
29. A magnetic head assembly as claimed in claim 28 wherein the tantalum layer has a thickness in a range of 20-100 Å.
30. A magnetic head assembly as claimed in claim 29 including:
the free layer structure having a nickel iron (NiFe) layer and a cobalt iron (CoFe) layer; and
the cobalt iron (CoFe) layer being located between the nickel iron (NiFe) layer and the ruthenium (Ru) layer.
31. A magnetic head assembly as claimed in claim 30 wherein the cobalt iron (CoFe) layer has a thickness in a range of 3-20 Å.
32. A magnetic head assembly as claimed in claim 31 including:
a ferromagnetic second shield layer;
a nonmagnetic isolation layer; and
the isolation layer being located between the second shield layer and the first pole piece layer.
33. A magnetic head assembly as claimed in claim 31 wherein the pinned layer structure is an antiparallel (AP) pinned layer structure that comprises:
first and second ferromagnetic pinned layers with the first pinned layer being pinned by the pinning layer in a first direction; and
an antiparallel coupling layer located between the first and second pinned layers so that the second pinned layer is pinned antiparallel to said first direction in a second direction.
34. A magnetic head assembly as claimed in claim 31 wherein the pinned layer structure consists of a single ferromagnetic pinned layer.
35. A magnetic disk drive that includes at least one slider, the slider supporting a magnetic head assembly that has a write head and a read head, the disk drive comprising:
the write head including:
first and second pole piece layers;
each of the first and second pole piece layers having a yoke portion located between a pole tip portion and a back gap portion;
a nonmagnetic electrically insulative write gap layer located between the pole tip portions of the first and second pole piece layers;
an insulation stack with at least one coil layer embedded therein located between the yoke portions of the first and second pole piece layers; and
the first and second pole piece layers being connected at their back gaps portions; and
the read head including:
a spin valve sensor that has first and second side edges;
first and second lead layers connected to the first and second side edges of the spin valve sensor;
nonmagnetic electrically insulative first and second read gap layers;
the spin valve sensor and the first and second lead layers being located between the first and second read gap layers;
a ferromagnetic first shield layer; and
the first and second read gap layers being located between the first shield layer and the first pole piece layer; and
the spin valve sensor including:
a ferromagnetic free layer structure;
a ferromagnetic pinned layer structure;
a nonmagnetic electrically conductive spacer layer located between the free layer structure and the pinned layer structure;
an antiferromagnetic pinning layer exchange coupled to the pinned layer structure for pinning a magnetic moment of the pinned layer structure;
the pinned layer structure being located between the pinning layer and the spacer layer;
a cap layer structure having a ruthenium (Ru) layer and a metal oxide layer; and
the ruthenium (Ru) layer interfacing the free layer structure and being located between the metal oxide layer and the free layer structure; and
a housing;
a magnetic disk rotatably supported in the housing;
a support mounted in the housing for supporting the magnetic head assembly with its ABS facing the magnetic disk so that the magnetic head assembly is in a transducing relationship with the magnetic disk;
means for rotating the magnetic disk;
positioning means connected to the support for moving the magnetic head assembly to multiple positions with respect to said magnetic disk; and
processing means, that is connected to the means for rotating the magnetic disk, the positioning means and the magnetic head assembly for rotating the magnetic disk, positioning the magnetic head assembly relative to the rotating magnetic disk and exchanging signals with the magnetic head assembly.
36. A magnetic disk drive as claimed in claim 35 including:
a ferromagnetic second shield layer;
a nonmagnetic isolation layer; and
the isolation layer being located between the second shield layer and the first pole piece layer.
37. A magnetic disk drive as claimed in claim 35 wherein the ruthenium (Ru)layer has a thickness in a range of 3-30 Å.
38. A magnetic disk drive as claimed in claim 37 wherein the metal oxide layer is selected from a group comprising nickel oxide (NiO), tantalum oxide (Ta 2 O 3 ) and aluminum oxide (Al 2 O 5 ).
39. A magnetic disk drive that includes at least one slider, the slider supporting a magnetic head assembly that has a write head and a read head the disk drive comprising:
the write head including:
first and second pole piece layers;
each of the first and second pole piece layers having a yoke portion located between a pole tip portion and a back gap portion;
a nonmagnetic electrically insulative write gap layer located between the pole tip portions of the first and second pole piece layers;
an insulation stack with at least one coil layer embedded therein located between the yoke portions of the first and second pole piece layers; and
the first and second pole piece layers being connected at their back gaps portions; and
the read head including:
a spin valve sensor that has first and second side edges;
first and second lead layers connected to the first and second side edges of the spin valve sensor;
nonmagnetic electrically insulative first and second read gap layers;
the spin valve sensor and the first and second lead layers being located between the first and second read gap layers;
a ferromagnetic first shield layer; and
the first and second read gap layers being located between the first shield layer and the first pole piece layer; and
the spin valve sensor including:
a ferromagnetic free layer structure;
a ferromagnetic pinned layer structure;
a nonmagnetic electrically conductive spacer layer located between the free layer structure and the pinned layer structure;
an antiferromagnetic pinning layer exchange coupled to the pinned layer structure for pinning a magnetic moment of the pinned layer structure;
the pinned layer structure being located between the pinning layer and the spacer layer;
a cap layer structure having a ruthenium (Ru) layer and a metal oxide layer; and
the ruthenium (Ru) layer being located between the metal oxide layer and the free layer structure;
the ruthenium (Ru) layer having a thickness in a range of 3-30 Å;
the metal oxide layer being selected from a group comprising nickel oxide (NiO) tantalum oxide (Ta 2 O 3 ) and aluminum oxide (Al 2 O 5 ); and
the metal oxide layer having a thickness in a range of 5-50 Å;
a housing;
a magnetic disk rotatably supported in the housing;
a support mounted in the housing for supporting the magnetic head assembly with its ABS facing the magnetic disk so that the magnetic head assembly is in a transducing relationship with the magnetic disk;
means for rotating the magnetic disk;
positioning means connected to the support for moving the magnetic head assembly to multiple positions with respect to said magnetic disk; and
processing means, that is connected to the means for rotating the magnetic disk, the positioning means and the magnetic head assembly for rotating the magnetic disk, positioning the magnetic head assembly relative to the rotating magnetic disk and exchanging signals with the magnetic head assembly.
40. A magnetic disk drive as claimed in claim 39 wherein the cap layer structure further includes a tantalum (Ta) layer with the metal oxide layer being located between the ruthenium (Ru) layer and the tantalum (Ta) layer.
41. A magnetic disk drive as claimed in claim 40 wherein the tantalum layer has a thickness in a range of 20-100 Å.
42. A magnetic disk drive as claimed in claim 41 including:
the free layer structure having a nickel iron (NiFe) layer and a cobalt iron (CoFe) layer; and
the cobalt iron (CoFe) layer being located between the nickel iron (NiFe) layer and the ruthenium (Ru) layer.
43. A magnetic disk drive as claimed in claim 42 wherein the cobalt iron (CoFe) layer has a thickness in a range of 3-20 Å.
44. A method of making a magnetic head assembly comprising the steps of:
making a read head as follows:
forming a ferromagnetic first shield layer;
forming a nonmagnetic electrically insulative first read gap layer on the first shield layer; and
forming a spin valve sensor on the first read gap layer;
the forming of the spin valve sensor comprising the steps of:
forming an antiferromagnetic pinning layer on the first read gap layer;
forming a pinned layer structure on the pinning layer;
forming a nonmagnetic electrically conductive spacer layer on the pinned layer structure;
forming a ferromagnetic free layer structure on the spacer layer; and
forming a cap layer structure on the free layer structure;
the forming of the cap layer structure comprising the steps of:
forming a ruthenium (Ru) layer directly on the free layer structure; and
forming a metal oxide layer on the ruthenium (Ru) layer.
45. A method as claimed in claim 44 wherein the pinned layer structure is formed as follows:
forming a ferromagnetic first pinned layer on the pinning layer;
forming an antiparallel coupling layer on the first pinned layer; and
forming a ferromagnetic second pinned layer on the antiparallel coupling layer.
46. A method as claimed in claim 44 wherein the pinned layer structure is formed as follows:
forming a single ferromagnetic layer on the pinning layer.
47. A method as claimed in claim 44 further including the steps of:
connecting first and second lead layers to first and second side edges of the spin valve sensor;
forming a nonmagnetic electrically insulative second read gap layer on the spin valve sensor and the first and second lead layers;
forming a write head on the second read gap layer;
the forming of the write head comprising the steps of:
forming a ferromagnetic first pole piece layer on the second read gap
layer wherein the first pole piece layer has a yoke region located between a pole tip region and a back gap region;
forming a nonmagnetic electrically insulative write gap layer on the first pole piece layer in the pole tip region;
forming an insulation stack with at least one coil layer embedded therein on the first pole piece layer in the yoke region;
the forming of the write gap layer and the forming of the insulation stack being in an unordered sequence with respect to each other; and
connecting the first and second pole piece layers together at the back gap region.
48. A method as claimed in claim 47 further including the steps of:
before forming the write head forming a second shield layer on the second read gap layer;
forming a nonmagnetic isolation layer on the second shield layer; and
said forming of the write head being on said isolation layer.
49. A method as claimed in claim 47 wherein the ruthenium (Ru) layer is formed with a thickness in a range of 3-30 Å.
50. A method as claimed in claim 49 wherein the metal oxide layer is formed from a group comprising nickel oxide (NiO), tantalum oxide (Ta 2 O 3 ) and aluminum oxide (Al 2 O 3 ).
51. A method as claimed in claim 47 wherein the metal oxide layer is formed from a group comprising nickel oxide (NiO), tantalum oxide (Ta 2 O 3 ) and aluminum oxide (Al 2 O 3 ).
52. A method as claimed in claim 51 wherein the forming of the free layer structure further includes:
forming a ferromagnetic nickel iron (NiFe) first free layer on the spacer layer; and
forming a ferromagnetic cobalt iron (CoFe) second free layer on the first free layer.
53. A method as claimed in claim 52 wherein the forming of the cap layer structure further includes forming a tantalum (Ta) layer on the metal oxide layer.
54. A method of making a magnetic head assembly comprising the steps of:
making a read head as follows:
forming a ferromagnetic first shield layer;
forming a nonmagnetic electrically insulative first read gap layer on the first shield layer; and
forming a spin valve sensor on the first read gap layer;
the forming of the spin valve sensor comprising the steps of:
forming an antiferromagnetic pinning layer on the first read gap layer;
forming a pinned layer structure on the pinning layer;
forming a nonmagnetic electrically conductive spacer layer on the pinned layer structure;
forming a ferromagnetic free layer structure on the spacer layer; and
forming a cap layer structure on the free layer structure;
the forming of the cap layer structure comprising the steps of:
forming a ruthenium (Ru) layer on the free layer structure;
forming a metal oxide layer on the ruthenium (Ru) layer;
the ruthenium (Ru) layer being formed with a thickness in a range of 3-30 Å; and
the metal oxide layer being formed from a group comprising nickel oxide (NiO), tantalum oxide (Ta 2 O 3 ) and aluminum oxide (Al 2 O 3 ; and
the metal oxide layer being formed with a thickness in the range of 5-50 Å; further making the read head as follows:
connecting first and second lead layers to first and second side edges of the spin valve sensor;
forming a nonmagnetic electrically insulative second read gap layer on the spin valve sensor and the first and second lead layers; and
forming a write head on the second read gap layer:
the forming of the write head comprising the steps of:
forming a ferromagnetic first pole piece layer on the second read gap layer wherein the first pole piece layer has a yoke region located between a pole tip region and a back gap region;
forming a nonmagnetic electrically insulative write Rap layer on the first pole piece layer in the pole tip region;
forming an insulation stack with at least one coil layer embedded therein on the first pole piece layer in the yoke region;
the forming of the write gap layer and the forming of the insulation stack being in an unordered sequence with respect to each other; and
connecting the first and second pole piece layers together at the back gap region.
55. A method as claimed in claim 54 wherein the forming of the cap layer structure further includes forming a tantalum (Ta) layer on the metal oxide layer.
56. A method as claimed in claim 55 wherein the tantalum (Ta) layer is formed with a thickness in a range of 20-100 Å.
57. A method as claimed in claim 56 wherein the forming of the free layer structure further includes:
forming a ferromagnetic nickel iron (NiFe) first free layer on the spacer layer; and
forming a ferromagnetic cobalt iron (CoFe) second free layer on the first free layer.
58. A method as claimed in claim 57 wherein the cobalt iron (CoFe) second free layer is formed with a thickness in the range of 3-20 Å.
59. A method as claimed in claim 58 further including the steps of:
before forming the write head forming a second shield layer on the second read gap layer;
forming a nonmagnetic isolation layer on the second shield layer; and
said forming of the write head being on said isolation layer.
60. A method as claimed in claim 58 wherein the pinned layer structure is formed as follows:
forming a ferromagnetic first pinned layer on the pinning layer;
forming an antiparallel coupling layer on the first pinned layer; and
forming a ferromagnetic second pinned layer on the antiparallel coupling layer.
61. A method as claimed in claim 58 wherein the pinned layer structure is formed as follows:
forming a single ferromagnetic layer on the pinning layer.Cited by (0)
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